JPH0134792Y2 - - Google Patents

Description

[Detailed description of the invention] (Prior art and its disadvantages) Conventionally, when connecting internally coated steel pipes, in order to prevent corrosion of the pipe end face and prevent liquid leakage from the joint, for example, A pipe joint, as shown in No. 2, in which a female thread is provided on the inner circumferential surface of the open end, a groove is provided along the circumferential direction on the inner circumferential surface of the deep part, and a jetty is provided in the deep part of the female thread along the circumferential direction. A pipe joint has been proposed in which one end of a short cylindrical body is brought into contact with the jetty side surface of the main body, and an annular packing is installed between the short cylindrical body and the pipe joint main body.

Since an anticorrosive coating is usually provided on the inner surface of the pipe joint body, the surfaces of the groove and the jetty are also coated with the anticorrosive coating. however,
In the case of the conventional pipe fittings mentioned above, when screwing an internally coated steel pipe with a male thread on the outer peripheral surface of the tube end into the female thread of the pipe fitting and tightening it, if it is tightened too much, the contact surface with the short cylinder will cause a bulge. The anticorrosion coating on the surface is damaged,
This has resulted in the disadvantage that the bare surface of the joint body is exposed, corrosion occurs from the exposed portion, and red water is generated.

(Purpose) In view of the above-mentioned drawbacks, the present invention has been developed to provide a cylindrical structure that covers the end face of the short cylinder on the side that comes into contact with the jetty side of the pipe joint body coated with an anticorrosive coating in conventional pipe joints. The purpose of the present invention is to provide a pipe joint in which the end face of the short cylinder does not come into direct contact with the anticorrosive coating on the side surface of the jetty and does not generate red water by extending the annular packing along the outer peripheral surface of the short cylinder. It is something.

(Structure) The gist of the present invention is that a female thread is provided on the inner circumferential surface of the opening end, a groove is provided along the circumferential direction on the inner circumferential surface of the deep part, and a jetty is provided in the deep part of the female thread along the circumferential direction. on the side surface of the jetty of the pipe joint body, where at least the surfaces of the groove and the jetty are coated with an anticorrosive coating,
A pipe joint in which one end surface of a short cylinder is brought into contact with the short cylinder so as to have the same axis, and a cylindrical annular packing is installed between the short cylinder and the pipe joint, wherein the cylindrical annular packing The pipe joint is characterized in that it extends along the outer peripheral surface of the short cylinder so as to cover the end face of the short cylinder on the side that comes into contact with the side surface of the jetty.

Hereinafter, the present invention will be explained with reference to embodiments of the drawings.

Reference numeral 1 denotes a pipe joint body, which has a tapered female thread 11 on the inner peripheral surface of its end, a groove 12 along the circumferential direction on the inner peripheral surface of the deep part, and a circumferential groove 12 on the inner peripheral surface of the deep part. A jetty 13 is provided along the direction,
An annular notch 131 is provided on the inner circumference of the side surface of the jetty 13, and the surfaces of the groove 12 and the jetty 13 are coated with an anticorrosive coating 14 made of synthetic resin or the like.

2 is a short cylinder. The short cylindrical body 2 is made of a material that does not deform even when an external force is applied to it and is corrosion-resistant, such as a stainless steel tube, and has a flange 21 provided outwardly at one end thereof. The inner diameter of the short cylinder 2 is approximately the same as the inner diameter of the jetty 13 of the pipe joint body 1, and its length is longer than the width of the groove 12 of the pipe joint body 1. This short cylindrical body 2 has the same axis as the side surface of the jetty 13 of the pipe joint body 1, that is, the notch 131, and the flange 21 is brought into contact with the same axis.

Reference numeral 3 denotes a cylindrical annular packing made of an elastic material, and as shown in FIG. It is slightly longer than the length of the short cylindrical body 2. The large diameter portion 31 has a thickness slightly larger than the distance between the short cylinder body 2 and the tapered female threaded portion 11, and has a notch 311 provided along the circumferential direction on the outer circumferential surface, and the notch 311 is recessed. Groove 1
2 and the corner of the female threaded portion 11. The width of the small diameter portion 32 is approximately the same as the width of the groove 12 and is smaller than the diameter of the groove 12,
Notch 1 of jetty 13 along the outer peripheral surface of short cylinder 2
It extends so as to cover the end surface of the flange 21 that comes into contact with the flange 31 . The annular packing 3 may simply be attached to the outer periphery of the short cylindrical body 2, but the small diameter portion 3
It is preferable that 2 is bonded and integrated by baking or other means, since this prevents the annular packing from becoming threaded due to co-rotation of the short cylindrical body when the inner-coated steel pipe is connected.

The annular packing 3 has the notch 311 connected to the groove 12.
It is attached between the short cylindrical body 2 and the pipe joint body 1 by being locked to the corner of the tube.

The short cylindrical body 2 and the annular packing 3 are attached to the pipe joint body 1.
For example, as shown in FIG. 2, an annular packing 3 is attached to the outer periphery of the short cylindrical body 2, and this is inserted into the pipe fitting main body 1, and the notch 3 is inserted.
11 is locked to the corner between the side wall of the groove 12 and the female threaded part 11, a part of the annular packing 3 is pressed between the tapered female threaded part 11 and the short cylindrical body 2, and the short cylindrical body 2 The pipe joint of the present invention is formed by abutting and fixing the flange portion 21 and one end surface of the small diameter portion 32 of the annular packing 3 to the notch 131 of the jetty 13 of the pipe joint body 1 (see Fig. 1). .

If the annular packing 3 is installed in a pressed state between the tapered female threaded portion 11 of the pipe joint body 1 and the short cylindrical body 2 as in the above embodiment, the annular packing 3 is attached to the short cylindrical body 2 and its outer circumference. The annular packing 3 is attached so as to have the same axis as the jetty 13 of the pipe joint body 1.

Further, an annular notch 131 is provided on the inner circumference of the side surface of the jetty 13, and the short cylindrical body 2 is provided in the notch 131.
When the flange 21 is fitted, the short cylindrical body 2 can be reliably fixed at a predetermined position on the jetty 13. When the flange 21 of the short cylindrical body 2 is fitted into the notch 131 of the jetty 13 in this way, the annular packing 3 is not necessarily inserted between the tapered female threaded part 11 of the pipe joint body 1 and the short cylindrical body 2. It is not necessary to attach it in a pressed state.

Next, a mode of use of the embodiment of the present invention shown in FIG. 1 will be explained with reference to FIG. 3.

Reference numeral 4 denotes an inner-coated steel pipe connected by a pipe joint, and a corrosion-resistant coating layer 42 made of synthetic resin or the like is provided on the inner surface of the steel pipe 41, and a tapered male threaded portion 43 is provided on the outer peripheral surface of the pipe end. Pipe fitting body 1
When the tapered male threaded part 43 of the internally coated steel pipe 4 is screwed into the tapered female threaded part 11 of the internally coated steel pipe 4 and tightened, the end surface of the internally coated steel pipe 4 first comes into contact with the annular packing 3, and when further tightened, the annular packing 3
is compressively deformed, but since it is supported by the short cylindrical body 2, it deforms toward the space of the groove 12 without bulging inward, and the outer circumferential surface of the short cylindrical body 2 and the inner circumferential surface of the groove 12 and is effectively compressed by the tube end surface of the inner-coated steel pipe 4, and seals the front side of the threaded portion of the tapered female thread 11 and the tapered male thread 43.

Note that the notch 13 of the jetty 13 in the above embodiment
1. The flange 21 of the short cylindrical body 2 is not necessarily essential.

The joint of the present invention is constructed as described above, and the cylindrical annular packing is arranged along the outer circumferential surface of the short cylindrical body so as to cover the end face of the short transparent body on the side of the pipe joint body that comes into contact with the jetty side surface. Since the pipe joint is extended, when an internally coated steel pipe is screwed onto the female thread of this pipe joint and tightened, even if it is over-tightened, the anti-corrosion coating on the jetty part will not directly contact the short cylinder like in a conventional pipe joint. The surface of the skin will not be exposed due to damage caused by the surface, thus preventing the generation of red water and ensuring clean water quality.

Moreover, since the elastic body covering the end face of the short cylinder body is integrally installed by extending from the annular packing installed between the pipe joint body and the short cylinder body, the elastic body that covers the end face of the short cylinder body is simply attached to the annular packing on the jetty side of the pipe joint body. Compared to a structure in which one end of a short cylindrical body is brought into contact with an elastic body interposed, when screwing an internally coated steel pipe, even if the elastic body is excessively compressed, the elastic body will not fall off to the inner surface of the tube, and the complete Can do stickers.

[Brief explanation of drawings]

Fig. 1 is a partially cutaway front view showing an embodiment of the present invention, Fig. 2 is a partially cutaway front view showing an annular packing used in the embodiment of the present invention, and Fig. 3 is a partially cutaway front view showing an embodiment of the present invention. FIG. 2 is a partially cutaway front view showing how the device is used. 1...Pipe joint body, 11...Female thread portion, 12...
... Concave groove, 13 ... Jetty, 131 ... Notch, 1
4... Corrosion-proof coating, 2... Short cylindrical body, 21... Flange, 3... Annular packing, 31... Large diameter part, 3
2... Small diameter part, 311... Notch part.

Claims (1)

[Scope of Claim for Utility Model Registration] 1. A female thread is provided on the inner circumferential surface of the opening end, and a groove is provided along the circumferential direction on the inner circumferential surface of the inner part,
A jetty is provided in the inner part along the circumferential direction, and at least the groove and the surface of the jetty are coated with an anticorrosion coating. In a pipe joint in which one end surface is in contact with the short cylinder and a cylindrical annular packing is installed between the short cylinder and the pipe joint, the cylindrical annular packing extends along the outer circumferential surface of the short cylinder, A pipe joint characterized in that the pipe joint extends so as to cover the end face of the short cylindrical body on the side that comes into contact with the side surface of the jetty. 2. Scope of Utility Model Registration Claim 1, wherein a notch is provided along the circumferential direction on the outer peripheral surface of the annular packing, and the notch is engaged with the corner of the side wall of the groove and the female thread. Pipe fittings listed. 3. The pipe joint according to claim 1 or 2, wherein the annular packing is attached to the female threaded portion of the pipe joint body in a pressed state.